Detection of fluorescent signals finds wide applications in a variety of situations and under a variety of conditions. Fluorescence has many advantages as a means of generating a detectable signal. Fluorescence does not suffer from the many disadvantages of a radioactive label, while in many cases it provides for a high level of sensitivity.
There is substantial interest in being able to obtain fluorescence at longer wavelengths, where there is less interference from light resulting from scattering from components in the medium being irradiated. By providing for combinations of dyes with long Stokes shifts, one can achieve high sensitivity fluorescence detection of DNA, where the dye becomes bound to DNA and provides for a shift in the spectral properties of the resulting dimer.